1. Field of the Invention
This invention is related to an electrical connector that is used to terminate twisted pair wires. This invention is also related to electrical connectors that employ slotted beam or insulation displacement contacts or terminals to establish an electrical connector with insulated wires. More particularly, this invention is also related to electrical connectors that can be used to improve inductive and capacitive electrical coupling between individual wires in a twisted pair and to reduce crosstalk between adjacent twisted pairs for higher frequency transmission, such as 100 Mhz signals.
2. Description of the Prior Art
A conventional 110 style electrical connector used to terminate twisted pair telecommunications cables is shown in FIG. 1. These connectors 110 employ slotted beam or insulation displacement contact terminals 150. The connector shown in FIG. 1 is a four position connector that is used to terminate tip and ring wires in a two pair cable to a printed circuit board using compliant pin sections 156. The four terminals 150 are positioned side by side with the planar slotted beam portions 152 of the four terminals located in the same plane. Terminals 150 are received in cavities 136 in an insulated housing 112 that extend into tapered divider walls 124, center walls 120 and side walls 122 located on the top of the housing 112. These walls 120, 122, 124 define channels into which wires are inserted. Wires inserted laterally of their axes into these channels are inserted into the wire contact slots 174 in the slotted beams 152 of the terminals 150. The edges of the slotted beam defining the wire contact slots penetrate the wire insulation and establish a gas tight electrical connection to the wire. Terminals 150 are held in the housing 112 by tabs 162 struck from the sides of the terminal and by plastic inserted into the terminal opening left when the tabs 162 are formed. An electrical connector of similar construction that is used for splicing separate twisted pair cables is disclosed in U.S. Pat. No. 5,409,404,
Another connector that uses slotted beams or insulation displacement contacts with twisted pair cables is shown in U.S. Pat. No. 4,171,857. In that patent the terminals are fixedly disposed at an angle offset by about forty-five degrees with respect to a wire slot in a housing clamping element. That prior art connector is used to connect two wires to opposite bifurcated sections of the same terminal. The edges of the terminal element are offset at an angle so that the edges of the wire slot penetrate through the insulation of a wire and connect to the wire conductor.
Each of these prior art connectors is primarily intended for use with conventional twisted pair cable of the type commonly used for telephone communications. Recently twisted pair cable has been increasingly used for higher speed or higher frequency applications such as networked data communications. Standard twisted pair cable is not suitable for many of these applications because the transmission characteristics of standard twisted pair cable and twisted pair connectors are not satisfactory for these higher frequency applications. Therefore new standards for twisted pair cable suitable for higher frequencies have emerged. Category 5 twisted pair cable is one such cable. These cables are more tightly twisted to increase inductive and capacitive electrical coupling between individual wires forming each twisted pair. More stringent restrictions on crosstalk, and especially near end crosstalk (NEXT), have also been placed on these higher performance twisted pair cables. In many instances standard electrical connectors developed for use in the telephone industry can degrade the performance of twisted pair cable installations intended for use in higher frequency applications. These standard electrical connectors are however widely used and common footprints and installation tooling are widely known in the industry. There is therefore a desire to retain the well understood characteristics of these standard electrical connectors, but at the same time improve their performance.